blakely



'.(No Model.) Y sheets-smet 1.

' W. BLAKELY.

GRANK FOR BIGYGLES.

NQ..4.46,2'80. Patented Peb.. 10.1891.

' (No Model.) 2 Sheets-Sheet 2.

W.I BLAKBLY. @RANK FR BICYLBS.

N0.446,28o. Patemdleb. 10,1891.

UNITED STATESV PATENT @erica IVILLIAM BLAKELY, OF B'OURNEMOUTH VEST,ENGLAND.

CRANK FOR BlcYctEs.

SPECIFICATIG forming part of Letters Patent No.'446,280, dated February10, 1891.

Application led J'uly l, 1890. Serial No. 357,409.. (No model.)

To all whom, t may concern:

Be it known that I, WILLIAM BLAKELY, engineer, of Vernon, Princess Road,Bournemouth IVest,in the county of Hants, England,

have invented new and useful Improvements in the Construction of theCranks and Crank-k Shafts of Cycles and other Machines and the BearingsTherefor, of which the following is a full, clear, and exactdescription.

My invention relates to the construction of the cranks and crank-shaftsof cycles and other light machines, and is illustrated in theaccompanying drawings, forming part of this specification, wherein-Figure l represents a longitudinal section, Fig. 2 a face view, and Fig.8 a cross-section, (online 3 3, Fig. 1,) of a bicycle-crank arm. Figs. 4and 5 show longitudinal and crosssectional views of modifiedconstructions of zo crank-axle.

Similar letters of reference indicate like parts in all the figures.

According to my invention I build up the crank of an external shellcomposed of two 2 5 stamped sheet-steel plates a a upon a core of toughwood b, whereby I am enabled to combine lightness with strength. Theplates a a are both stamped up of channeled section, as shown incross-section in Fig. 3, so that their 3o iiangesbutt-joint along theedges of the crankarm, as at c c, and they are corrugated longitudinallyto give increased stiffness. They embrace the wood core, as shown, thewhole being firmly united by rivets d. The crankarm is slotted at t', atwhich point the wood core is replaced or strengthened by metal linings kto take the wear. The ends of the crankaxle e-are longitudinally tinted,as shown in Fig. l, and the parts of plates a a which form 4o the eyes fof the crank-arms are stamped with notched edges corresponding to theutes of the axle, so as when driven onto the ends of the axle they willbe securely keyed thereon by the interlocking tintes without the use ofany loose' keys. The flutes may continue `throughout the length of theaxle e, the flutes at the parts which form the journals being eitherfilled up with agate or other hard material to form a cylindricaljournal, as at g, or 5o being left wholly or partially fluted for thepurpose of holding lubricant. The utes at the other parts of the axle'orshaft serve to the pedal is mounted, is fitted to slide in thelongitudinal slottl in the crank-arm, the edges of said slot being linedwith metal 7c, as above mentioned. The pin 7L is carried by a bar l,fitted to slide telescopically within the crankarm, the wood core ofwhich is made hollow to receive it. This barZ is of oblong crosssection,so as to have the necessary transverse strength, and it is surrounded bya spiral spring m, of oval form in section, which is confined between across-pin Z at the inner end and a shoulder b on the core of thecrankarm, so as to tend to draw the crank-pin inward to its shortestradius. It is shown in its mid-position in Fig. l, and is locked ineither of these positions by a spring locking-bolt n, sliding through atransverse slot in the crankarm and adapted to engage with either ofthree notches o o2 o3 in the edge of the arm Z. The locking-bolt n isdrawn into engagement with one of said notches by a spring 1J, and thehead of the locking-bolt projects from the face of the crank-arm in suchposition that it may be conveniently pressed inward to disengage thebolt from the notch in the arm Z by a side motion of the riders foot atthe same time that by pressure of the same foot on the pedal thecrank-pin may be moved along the crank-arm to a greater radius, or

by relaxing the pressure of the foot the spring m is permitted to act soas to draw the crankpin inward to a less radius, as the case may be, thebolt in either case relooking the sliding bar automatically. Thus theradius of the cranks or pedals may be altered by the rider withoutdismounting and while the Vehicle is running.

Fig. 4 shows a inode of constructing an axle or shaft of two or morethin steel or other metal tubes r s, shrunk the one on the other andupon a core t, formed of a metal rod of triangular (or it may becrnciform) cross-section.

Fig. 5 shows a similar tubular construction, the outer tube being shrunkon the inner one, which is filled by a core u of hard tough wood,

IOO

such as lance-wood, iron wood, or hickory dried, and forced tightly intothe inner tube. By these constructions a light and very stift shaft oraxle is produced, which is not likely to spring or bend under the Weightof a heavy rider.

Having now particularly described and ascertained the nature of the said-invention and in what manner the same is to be performed, I declarethat what I claim is- 1. The herein-described construction of crank-armsof a shell formed of stamped steel plates clamped upon a wood core, asspecified.

2. An improved crank-arm formed of a core and an external shell ofsheet'metal and providedwith a notched eye,substantiallyas described.

3. Fluting the axle-journals and filling the flutes-With agate or otherhard material, as specified.

4. The combination, With a luted' axle, of a crank formed of a core anda sheet-metal shell and provided with an eye notched to correspond withthe utes of the axle, substantially as herein shown and described.

. 5. The combination of a hollow crank-arm,

a bar to which the pedalis connected, fitted toslide in the crank-arm, aspring` for drawing the bar into the crank-arm, and-a springpressed boltengaging the bar to lock it in position in the said crank-arm,substantially as described.

6. The combination, with a hollow crankarm having its lower end slotted,of a bar to which the pedal is connected, fitted to slide projectinginto the slot thereof, a spring snrronnding the bar in the crank-arm,and a spring-pressed bolt for engaging the bar to 'lock it in positionin the crank-arm, substantially as described. Y

The foregoing specification of my improvements in the construction ofthe cranks and crank-shafts of cycles and other machines and.

the bearings therefor signed by lne this 10th day of April, 1890.

WILLIAM BLAKELY. W'itnesses: l

GEO. J. B. NUNKLIN, WV. J. NORWOOD, Both of 17 GracechurchStreet,London, E. 0.,

Notarys Clerks.

35 in the'crank-arm and having its lower end

